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Home >> Mercury >> 2007 >> Montego Base, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test DK: Accelerator Pedal Position (App) Sensor Through Pinpoint Test DW: Heated Oxygen Sensor (Ho2S) - (Except Diesel & Hybrid) >> PINPOINT TEST DR: Camshaft Position (CMP) Sensor >> Test Procedure
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Test Procedure

  1. DR1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 
    • Are DTCs P0340, P0344, P0345, or P0349 present? 
    Yes No
    For DTCs P0340, P0344, P0345 or P0349, GO to  DR2. For all others, GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. DR2 CONTINUOUS MEMORY DTCS P0340, P0344, P0345 AND P0349: CHECK IF THE ENGINE STARTS 
    • Attempt to start the engine.
    • Does the engine start? 
    Yes No
    GO to  DR3. RETURN to the SYMPTOM CHARTS article, Symptom Charts for further direction.
  3. DR3 CLEAR AND ATTEMPT TO RETRIEVE THE DTC 
    NOTE: If DTCs P0340, P0344, P0345, or P0349 are present, ignition, alternator noise, RFI and CKP concerns should be considered.
    NOTE: For vehicles with variable camshaft timing (VCT), concerns with the engine oil level, oil filter, oil contamination, or the VCT system may cause camshaft positioning errors.
    • Key ON, engine OFF.
    • Clear the PCM DTCs.
    • Key ON, engine running.
    • Increase engine speed to greater than 1,500 RPM for 10 seconds. Repeat this 3 times.
    • Retrieve the continuous memory DTCs.
    • Are DTCs P0340, P0344, P0345 or P0349 present? 
    Yes No
    GO to  DR4. refer to PINPOINT TEST Z .
  4. DR4 CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE 
    NOTE: If the generator/regulator is electrically noisy, the noise decreases when the B+ connector is disconnected.
    • PCM connector connected.
    • CMP Sensor connector connected.
    • Key ON, engine running.
    • Monitor the generator for an audible electric noise.
    • Key in OFF position.
    • Generator/regulator B+ connector disconnected.
    • Key ON, engine running.
    • With the engine running, determine if the generator is still noisy.
    • Does the noise remain constant when the B+ connector is disconnected? 
    Yes No
    For continuous memory DTCs P0340 or P0344, GO to  DR5.
    For continuous memory DTCs P0345 or P0349, GO to  DR13.    		 REFER to the appropriate CHARGING SYSTEM - GENERAL INFORMATION article to diagnose the generator is noisy symptom.
  5. DR5 DETERMINE THE CMP SENSOR PHYSICAL TYPE 
    • Key in OFF position.
    • Is the CMP sensor a synchronizer (gear driven) type? 
    Yes No
    GO to  DR6. GO to  DR7.
  6. DR6 VERIFY THE CORRECT INSTALLATION OF THE CMP SENSOR 
    NOTE: A CMP sensor identifies the cylinder 1 power stroke. A sensor that is improperly installed/indexed can identify the wrong cylinder as 1, produce a tip-in hesitation and generate DTC P0340.
    • Is the CMP sensor installed correctly? 
    Yes No
    GO to  DR7. INSTALL the CMP sensor correctly. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  7. DR7 DETERMINE THE CMP SENSOR ELECTRONIC TYPE 
    NOTE: The variable reluctance (VR) sensors have 2-wire connectors, Hall-effect sensors have 3-wire connectors.
    • Is the CMP sensor a VR type? 
    Yes No
    GO to  DR8. The CMP sensor is a Hall-effect type.
    GO to  DR19.
  8. DR8 CONTINUOUS MEMORY DTCS P0340 AND P0344: CHECK THE CMP SENSOR RESISTANCE 
    • Key in OFF position.
    • CMP Sensor connector disconnected.
    • Measure the resistance between:
      ( + ) CMP Sensor Connector, Component Side ( - ) CMP Sensor Connector, Component Side
      CMP SIGRTN
      CMP VRSRTN
      Vehicle Minimum Resistance (ohms) Maximum Resistance (ohms)
      Edge, MKX 586 2,033
      F-150 4.6L 1,978 5,590
      F-150, Mark LT 205 579
      MKZ 586 2,033
      All others 250 1,000
    • Is the resistance within specification? 
    Yes No
    GO to  DR9. INSTALL a new CMP sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  9. DR9 CHECK THE CMP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) Vehicle Battery
      CMP Negative terminal
    • Is the voltage less than 1 V? 
    Yes No
    GO to  DR10. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  10. DR10 CHECK THE CMP AND SIGRTN OR VRSRTN CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) CMP Sensor Connector, Harness Side
      CMP CMP
      SIGRTN SIGRTN
      VRSRTN VRSRTN
    • Are the resistances less than 5 ohms? 
    Yes No
    GO to  DR11. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  11. DR11 CHECK FOR A SHORT IN THE HARNESS BETWEEN THE PCM AND THE CMP SENSOR 
    • Measure the resistance between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) CMP Sensor Connector, Harness Side
      CMP SIGRTN
      CMP VRSRTN
    • Measure the resistance between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) Vehicle Battery
      CMP Negative terminal
      SIGRTN Negative terminal
      VRSRTN Negative terminal
    • Are the resistances greater than 10K ohms? 
    Yes No
    GO to  DR12. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  12. DR12 CHECK THE CMP SENSOR OUTPUT 
    • Key in OFF position.
    • Generator/regulator B+ connector connected.
    • CMP Sensor connector disconnected.
    • Key ON, engine running.
    • Digital multimeter (DMM) on low voltage AC scale.
    • Measure the voltage between:
      ( + ) CMP Sensor Connector, Component Side ( - ) CMP Sensor Connector, Component Side
      CMP SIGRTN
      CMP VRSRTN
    • Run the engine at approximately 2,500 RPM.
    • Is the voltage greater than 0.25 V? 
    Yes No
    For Expedition,
    Explorer 4.6L,
    Explorer Sport Trac 4.6L,
    F-150 5.4L,
    Mark LT,
    Mountaineer 4.6L,
    Mustang 4.6L, and
    Navigator, GO to  DR25.
    For all others, GO to  DR26.    		 INSTALL a new CMP sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  13. DR13 CONTINUOUS MEMORY DTCS P0345 AND P0349: CHECK THE CMP2 SENSOR RESISTANCE 
    • Key in OFF position.
    • CMP2 Sensor connector disconnected.
    • Measure the resistance between:
      ( + ) CMP2 Sensor Connector, Component Side ( - ) CMP2 Sensor Connector, Component Side
      CMP2 SIGRTN
      CMP2 VRSRTN
      CMP2 VRSRTN2
      Vehicle Minimum Resistance (ohms) Maximum Resistance (ohms)
      Edge, MKX 586 2,033
      F-150, Mark LT 205 579
      MKZ 586 2,033
      All others 250 1,000
    • Is the resistance value(s) within specifications? 
    Yes No
    GO to  DR14. INSTALL a new CMP2 sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  14. DR14 CHECK THE CMP2 CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) CMP2 Sensor Connector, Harness Side ( - ) Vehicle Battery
      CMP2 Negative terminal
    • Is the voltage less than 1 V? 
    Yes No
    GO to  DR15. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  15. DR15 CHECK THE CMP2 AND SIGRTN, VRSRTN, OR VRSRTN2 CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) CMP2 Sensor Connector, Harness Side
      CMP2 CMP2
      SIGRTN SIGRTN
      VRSRTN VRSRTN
      VRSRTN2 VRSRTN2
    • Are the resistances less than 5 ohms? 
    Yes No
    GO to  DR16. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  16. DR16 CHECK FOR A SHORT IN THE HARNESS BETWEEN THE PCM AND THE CMP2 SENSOR 
    • Measure the resistance between:
      ( + ) CMP2 Sensor Connector, Harness Side ( - ) CMP2 Sensor Connector, Harness Side
      CMP2 SIGRTN
      CMP2 VRSRTN
      CMP2 VRSRTN2
    • Measure the resistance between:
      ( + ) CMP2 Sensor Connector, Harness Side ( - ) Vehicle Battery
      CMP2 Negative terminal
      SIGRTN Negative terminal
      VRSRTN Negative terminal
      VRSRTN2 Negative terminal
    • Are the resistances greater than 10K ohms? 
    Yes No
    GO to  DR17. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  17. DR17 CHECK FOR A SHORT BETWEEN THE CMP AND THE CMP2 CIRCUITS 
    • CMP Sensor connector disconnected.
    • CMP2 Sensor connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      CMP CMP2
    • Is the resistance greater than 10K ohms? 
    Yes No
    GO to  DR18. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  18. DR18 CHECK THE CMP2 SENSOR OUTPUT 
    • Key in OFF position.
    • Generator/regulator B+ connector connected.
    • CMP2 Sensor connector disconnected.
    • Key ON, engine running.
    • DMM on low voltage AC scale.
    • Measure the voltage between:
      ( + ) CMP2 Sensor Connector, Component Side ( - ) CMP2 Sensor Connector, Component Side
      CMP2 SIGRTN
      CMP2 VRSRTN
      CMP2 VRSRTN2
    • Run the engine at approximately 2,500 RPM.
    • Is the voltage greater than 0.25 V? 
    Yes No
    For Expedition,
    Explorer 4.6L,
    Explorer Sport Trac 4.6L,
    F-150 5.4L,
    Mark LT,
    Mountaineer 4.6L,
    Mustang 4.6L, and
    Navigator, GO to  DR25.
    For all others, GO to  DR26.    		 INSTALL a new CMP2 sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  19. DR19 CONTINUOUS MEMORY DTCS P0340 AND P0344: CHECK THE VOLTAGE TO THE CMP SENSOR 
    • CMP Sensor connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) Vehicle Battery
      VPWR Negative terminal
      VBPWR Negative terminal
    • Is the voltage greater than 10 V? 
    Yes No
    GO to  DR20. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  20. DR20 CHECK THE PWRGND OR SIGRTN CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • Measure the voltage between:
      ( + ) Vehicle Battery ( - ) CMP Sensor Connector, Harness Side
      Positive terminal PWRGND
      Positive terminal SIGRTN
    • Is the voltage greater than 10 V? 
    Yes No
    GO to  DR21. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  21. DR21 CHECK THE CMP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) Vehicle Battery
      CMP Negative terminal
    • Is the voltage less than 1 V? 
    Yes No
    GO to  DR22. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  22. DR22 CHECK FOR AN OPEN CIRCUIT BETWEEN THE PCM AND CMP SENSOR 
    • Key in OFF position.
    • CMP Sensor connector disconnected.
    • Measure the resistance between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) PCM Connector, Harness Side
      CMP CMP
    • Is the resistance less than 5 ohms? 
    Yes No
    GO to  DR23. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  23. DR23 CHECK THE CMP CIRCUIT FOR A SHORT TO PWRGND OR SIGRTN IN THE HARNESS 
    NOTE: The measurement may be taken at the PCM or CMP connector, whichever is easier to access.
    • Measure the resistance between:
      ( + ) CMP Sensor Connector, Harness Side ( - ) CMP Sensor Connector, Harness Side
      CMP PWRGND
      CMP SIGRTN
    • Is the resistance greater than 10K ohms? 
    Yes No
    GO to  DR24. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  24. DR24 CHECK THE CMP SENSOR FOR CORRECT OPERATION 
    • PCM connector connected.
    • Connect a 5 amp fused jumper wire between the following:
      Point A CMP Sensor Connector, Harness Side Point B CMP Sensor Connector, Component Side
      VPWR VPWR
      VBPWR VBPWR
      SIGRTN SIGRTN
      PWRGND PWRGND
    • Key ON, engine running.
    • DMM on low voltage DC scale.
    • Measure the voltage between:
      ( + ) CMP Sensor Connector, Component Side ( - ) Vehicle Battery
      CMP Negative terminal
    • Does the voltage switch between LOW (less than 2 volts DC) and HIGH (greater than 8 volts DC)? 
    Yes No
    GO to  DR26. INSTALL a new CMP sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article.
    CLEAR the DTCs. REPEAT the self-test.
  25. DR25 CHECK THE VARIABLE CAMSHAFT TIMING (VCT) SYSTEM 
    NOTE: Only diagnose the bank indicated by the DTC.
    • Check the VCT system for correct operation.
    • Is a concern present? 
    Yes No
    REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DR26.
  26. DR26 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.
    • Is the concern still present? 
    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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